1. Field of the Invention
The present invention relates generally to boom-mounted attachments such as front end loader buckets, and more specifically to an improved carrier frame for a coupling utilized to mount the attachment on the boom.
2. Related Art
Many types of structures are available to connect a bucket or other device to the forward end of loader arms. Typically the device either includes a standard semi-permanent mounting arrangement wherein pins or bolts are manually connected between the arms and the attachment, or a relatively complex and more expensive quick coupler located on the arms and latchable automatically during mounting of the attachment. Making the necessary connections and disconnections during mounting and dismounting of the standard arrangement can be time-consuming and inconvenient.
To speed mounting and dismounting of the attachment, various types of quick coupling devices have been made available which reduce the number of times the operator has to leave the operator station during the procedures. Examples of such devices which typically include right-hand and left-hand mounting portions tied together by a large, rigid frame member are shown in U.S. Pat. No. 4,545,720; 3,876,091; 3,672,521 and 3,204,793. The frame member in the past has been made relatively strong and heavy since any distortion of the coupling would make connection of the attachment virtually impossible. The frame member keeps the right- and left-hand mounting portions fixed with respect to each other with very close tolerances, thereby resulting in manufacturing difficulties and high costs. The size and weight make the frame member difficult to handle and ship, and if the member is damaged complete replacement is often necessary. Although lighter frame members such as shown is U.S. Pat. No. 4,243,356 have been suggested, the connecting rod joining the end portions is subject to bending moments that can easily damage the structure.